Automotive headlamp apparatus synthesizing light distribution patterns of right and left lamp units

Abstract

An automotive headlamp apparatus includes a left lamp unit, a right lamp unit and a headlamp apparatus control unit. Each of the left lamp unit and the right lamp unit includes a bulb, a movable shade, a shade moving mechanism and a fixed shade. Each movable shade can advance or recede with respect to the light axis of the bulb, and forms an individual light distribution pattern for a low-beam by shielding part of a light at an advanced position while allowing formation of a partial shape of a light distribution pattern for a high-beam at a receded position. The fixed shade forms the partial shape of the light distribution pattern for a high-beam when the movable shade is located at the receded position. A pattern control unit determines each shape of the individual light distribution patterns by controlling each of the shade moving mechanisms in the left lamp unit and the right lamp unit, and also determines a shape of a synthesized light distribution pattern by superimposing each of the individual light distribution patterns one on another.

1. An automotive headlamp apparatus comprising:
 a left lamp unit and a right lamp unit that are installed apart from each other, located right and left in the automotive width direction, each of which is capable of forming an individual light distribution pattern; and 
 a pattern control unit that controls each shape of the individual light distribution patterns of high and low beams with cut-off lines of a horizontally extending light distribution pattern by controlling the left lamp unit and the right lamp unit, so as to form a synthesized light distribution pattern in which the individual light distribution patterns are superimposed, 
 wherein the left lamp unit includes: 
 a first light source that is capable of emitting a light in the automotive front direction through a first projection lens; 
 a first movable shade that is capable of advancing and receding with respect to the light axis of the first light source, that forms a first cut-off line by shielding part of the light from the first light source at an advanced position, the first cut-off line being to the left of a horizontally extending cut-off line of a light distribution pattern for a low-beam, and the first movable shade forms a portion of a light distribution pattern for a high-beam above the first cut-off line at a receded position; 
 a first shade moving mechanism that moves the first movable shade to an advanced or a receded position; and 
 a first fixed shade that forms a second cut-off line to the right of the horizontally extending cut-off line of the light distribution pattern for the low-beam when the first movable shade is at the receded position, 
 wherein the right lamp unit includes: 
 a second light source that is capable of emitting a light in the automotive front direction through a second projection lens; 
 a second movable shade that is capable of advancing and receding with respect to the light axis of the second light source, that forms the second cut-off line by shielding part of the light from the second light source at an advanced position, and wherein the second movable shade forms a portion of a light distribution pattern for a high-beam above the second cut-off line at a receded position; 
 a second shade moving mechanism that moves the second movable shade to an advanced or a receded position; 
 and a second fixed shade that forms the first cut-off line when the second movable shade is at the receded position 
 the first movable shade and the second movable shade are provided such that the light distribution pattern for a high-beam is formed when both of the movable shades are at the receded positions and 
 wherein the pattern control unit causes one or both of the first moveable shade and the second movable shade to advance or recede by controlling the first shade moving mechanism and second shade moving mechanism to form one of four synthesized light distribution patterns, and wherein the distribution pattern is determined by the pattern control unit. 
 
     
     
       2. The automotive headlamp apparatus according to  claim 1 , wherein shapes of the first movable shade and the first fixed shade in the automotive width direction are curved along a curved shape of the backside focal plane of the first projection lens, and
 shapes of the second movable shade and the second fixed shade in the automotive width direction are curved along a curved shape of the backside focal plane of the second projection lens. 
 
     
     
       3. The automotive headlamp apparatus according to  claim 1 , wherein an edge line portion of the first movable shade, which forms the first cut-off line, is arranged along the backside focal plane of the first projection lens at the advanced position, and
 an edge line portion of the second movable shade, which forms the second cut-off line, is arranged along the backside focal plane of the second projection lens at the advanced position. 
 
     
     
       4. The automotive headlamp apparatus according to  claim 1 , wherein the first shade moving mechanism moves the first movable shade to the advanced position so as to avoid forming the light distribution pattern for a high-beam when the pattern control unit is not controlling the first shade moving mechanism, and
 the second shade moving mechanism moves the second movable shade to the advanced position so as to avoid forming the light distribution pattern for a high-beam when the pattern control unit is not controlling the second shade moving mechanism. 
 
     
     
       5. The automotive headlamp apparatus according to  claim 1 , wherein the left lamp unit and the right lamp unit are capable of being rotated, and
 wherein the pattern control unit rotates the left lamp unit and the right lamp unit in a rotating direction of a vehicle based on an information from a steering sensor such that the center of the light distribution pattern is directed to the rotating direction. 
 
     
     
       6. The automotive headlamp apparatus according to  claim 1 , wherein the pattern control unit synchronizes the advancement or receding of the first movable shade and the advancement or receding of the second movable shade.